org.apache.datasketches.hive.theta

Class UnionSketchUDF

java.lang.Object

org.apache.hadoop.hive.ql.exec.UDF

org.apache.datasketches.hive.theta.UnionSketchUDF

public class UnionSketchUDF
extends org.apache.hadoop.hive.ql.exec.UDF

Hive union sketch UDF.

Constructor Summary

Constructors

Constructor and Description
UnionSketchUDF()

Method Summary

Modifier and Type	Method and Description
org.apache.hadoop.io.BytesWritable	evaluate(org.apache.hadoop.io.BytesWritable firstSketch, org.apache.hadoop.io.BytesWritable secondSketch) Main logic called by hive if sketchSize is not passed in.
org.apache.hadoop.io.BytesWritable	evaluate(org.apache.hadoop.io.BytesWritable firstSketch, org.apache.hadoop.io.BytesWritable secondSketch, int sketchSize) Main logic called by hive if sketchSize is also passed in.
org.apache.hadoop.io.BytesWritable	evaluate(org.apache.hadoop.io.BytesWritable firstSketch, org.apache.hadoop.io.BytesWritable secondSketch, int sketchSize, long seed) Main logic called by hive if sketchSize is also passed in.

Methods inherited from class org.apache.hadoop.hive.ql.exec.UDF

getRequiredFiles, getRequiredJars, getResolver, setResolver

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UnionSketchUDF

public UnionSketchUDF()

Method Detail

evaluate

public org.apache.hadoop.io.BytesWritable evaluate(org.apache.hadoop.io.BytesWritable firstSketch,
                                                   org.apache.hadoop.io.BytesWritable secondSketch,
                                                   int sketchSize,
                                                   long seed)

Main logic called by hive if sketchSize is also passed in. Union two sketches of same or different column.

Parameters:

firstSketch - first sketch to be unioned.

secondSketch - second sketch to be unioned.

sketchSize - final output unioned sketch size. This must be a power of 2 and larger than 16.

seed - using the seed is not recommended unless you really know why you need it.

Returns:

resulting sketch of union.

evaluate

public org.apache.hadoop.io.BytesWritable evaluate(org.apache.hadoop.io.BytesWritable firstSketch,
                                                   org.apache.hadoop.io.BytesWritable secondSketch,
                                                   int sketchSize)

Main logic called by hive if sketchSize is also passed in. Union two sketches of same or different column.

Parameters:

firstSketch - first sketch to be unioned.

secondSketch - second sketch to be unioned.

sketchSize - final output unioned sketch size. This must be a power of 2 and larger than 16.

Returns:

resulting sketch of union.

evaluate

public org.apache.hadoop.io.BytesWritable evaluate(org.apache.hadoop.io.BytesWritable firstSketch,
                                                   org.apache.hadoop.io.BytesWritable secondSketch)

Main logic called by hive if sketchSize is not passed in. Union two sketches of same or different column.

Parameters:

firstSketch - first sketch to be unioned.

secondSketch - second sketch to be unioned.

Returns:

resulting sketch of union.